The invention is based on a potentiometer as defined hereinafter. A potentiometer is already known in which to convert a mechanical input variable, such as a rotational angle, into a corresponding electrical output signal, such as an electric voltage, a wiper contact slide on a potentiometer track; the magnitude of the output signal depends on the input variable and thus on the position of the wiper contact on the potentiometer track.
A prerequisite for an electrically properly conducting connection between the wiper contact and the surface of the potentiometer track, and thus for proper potentiometer function, is that the wiper contact should rest flush on the surface of the potentiometer track. This is achieved for instance by disposing the wiper contact on a wiper lever in the form of a spring, which presses the wiper contact continuously against the surface of the potentiometer track with a slight pressure.
As the pressing force increases, the friction-caused wear to the surfaces of the wiper contact and potentiometer track increases as well. This wear takes the form of abraded material, for the most part material removed from the potentiometer track and the wiper contact. As the length of time in operation increases, this abraded material collects in loose, finely dispersed form on the wiper contact and potentiometer track surfaces, where it leads to increased contact resistance, which by definition has a negative impact on the output signal generated by the potentiometer.
Moreover, the abraded material dispersed finely over the surface of the potentiometer track acts as an abrasive medium, which leads to premature wear of the potentiometer track and wiper contact because of removal of material and thus shortens the potentiometer service life.